JPH05218733A - Simplified spaceship antenna reflector for being folded into vessel having limited volume - Google Patents

Abstract

(57) [Summary] [Object] The present invention aims to obtain a method for folding an antenna reflector used in a spacecraft into a container having a limited volume and deploying the antenna reflector from the container at the time of use. [Structure] The antenna reflector 10 is composed of an integral flexible material having a predetermined creep strain limit,
Deformation forces within the creep strain limit are applied to diametrically opposite positions 16, 18 near the edge of the reflector to keep the reflector 10 deformed by the string 20 until deployed and loosen the string 20. It is characterized in that the reflector 10 is returned to the original state when released from the deformed state.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to spacecraft antenna reflectors, and more particularly to a simplified spacecraft antenna reflector that facilitates folding and unfolding by a protective limited volume launch vessel.

[0002]

Spacecraft antenna reflectors are typically constructed as concave disks. The electrical design details for the reflector define the dimensions of the disc, in particular the diameter and the cross-section curvature. Spacecraft payload weight limitations limit the thickness of the reflector to such a level that the reflector is damaged by the dynamic forces associated with spacecraft launch. If the reflector is mounted in a typical operating configuration during launch (ie, placed on a support tower on the outer surface of a spacecraft), traction in the atmosphere and launch booster vibrations can damage the reflector in particular there is a possibility. Therefore, it is desirable to fold the reflector into a container of limited volume designed to protect the reflector from firing stress.

[0003]

The shape of the limiting container requires that the original antenna reflector shape be temporarily modified to fit inside the container during firing. After launch,
The reflector is released from the container and unfolded back to its original shape.

According to conventional techniques, antenna reflectors are designed with additional components to facilitate modification of the reflector shape for folding. One method that is often used is to use a segment reflector with a rib frame with cantilevers that deploy like an umbrella. However, these designs are expensive, complicate reflector manufacturing, and require complex systems for proper folding and unfolding of the reflector.

Therefore, while techniques for folding and unfolding spacecraft antenna reflectors are known, there is a need for further advances.

The present invention solves the technical need to provide a method of folding an integral flexible antenna reflector into a confining container and deploying the reflector from the container.

[0007]

SUMMARY OF THE INVENTION In general, the invention comprises a)
Deformation forces are applied to diametrically opposite positions near the edges of the reflector to place the reflector in its deformed state, b) maintaining the deformed state until deployed, and c) the reflector. Releasing the deformed state from the deformed state. In a particular embodiment, maintaining the reflector in a deformed state includes mounting restraining elements that are released upon deployment between diametrically opposite positions of the edges of the reflector.

According to the invention, the antenna reflector is provided with elastic properties which allow it to re-limit the shape of the reflector due to folding and return to its original shape upon deployment.

[0009]

1 (a) is a simplified perspective view of one embodiment of a manufactured flexible thin shell antenna reflector 10 of the present invention. 1 (b) is a front view thereof, and FIG. 1 (c) is a side view thereof. As shown in FIGS. 1A-1C, the reflector 10 includes a support mast 14
Is a parabolic shell having a centrally mounted coupling fixture 12.

The reflector 10 is composed of a single thin concave homogeneous sheet of flexible semi-rigid material such as graphite fiber reinforced plastic. The reflector 10 can be manufactured in the usual way, that is to say with the correct shape and exact form by means of multilayer stacks. The dimensions of the reflector 10 can be determined as usual. The reflector may be made of conductive or non-conductive material and coated with a conductive material.

According to the present invention, it is important that the reflector 10 be sufficiently flexible to be deformed to a folded configuration and deployed to a fully undeformed state. This requires a configuration in which the distortion due to the deformation of the reflector is below the creep strain limit, ie the level of force at which the reflector does not return to its original shape.

FIG. 2A is folded (deformed).
FIG. 3 is a top view of an embodiment of the antenna reflector 10 of the present invention in the form, and FIG. 2B is a side view thereof. FIG. 3 (a)
FIG. 3 is a top view of one embodiment of the present invention in an expanded state,
FIG. 3B is a side view thereof.

As shown in FIG. 2 (a), the reflector 10 is deformed by applying a uniform force on its periphery at points 16 and 18 located diametrically opposite. The reflector 10 can be maintained in the folded state by the string 20 shown in FIG. 2 (a) or a container (not shown), such as a space shuttle side rail in which the reflector 10 is folded. . If a string is used, it will be cut by the igniter 22. Alternatively, a material may be chosen that allows the reflector to deform at one temperature and remain deformed until deployed at another temperature. In short, the present invention does not limit the manner in which the reflector can be maintained and deployed in its deformed state.

Therefore, the present invention eliminates the disadvantages of the segment design by providing a single piece homogeneous reflector. The reflector can be manufactured using current manufacturing processes, modified to fit the protective launch container,
It can be returned to the desired shape upon deployment. No excess weight from the cantilever and motor is needed, and no motor control system is needed to effect the folding deformation or redeployment. There is no chain effect as there is no need for segmentation. The present invention eliminates the manufacturing steps required to segment conventional reflectors, including expensive cantilevers, ribs, and motor control systems, resulting in significant cost savings.

Although the present invention has been described herein with reference to a particular embodiment for a particular application, those skilled in the art will recognize additional modifications and embodiments within the scope.

Accordingly, all such adaptations, modifications, and embodiments should be within the scope of the invention as defined by the appended claims.

[Brief description of drawings]

1 is a simplified perspective view, top view, and side view of one embodiment of the manufactured antenna reflector of the present invention. FIG.

FIG. 2 is a top and side view of one embodiment of a folded antenna reflector of the present invention.

FIG. 3 is a top view and a side view of the expanded antenna reflector of the present invention.

[Explanation of symbols]

10 ... Reflector, 12 ... Fixture, 14 ... Support mast, 20 ... String, 22 ... Ignition device.

Claims (9)

[Claims] 1. A method of folding an integral flexible antenna reflector having a predetermined creep strain limit to accommodate in a container of limited volume and deploying the reflector from the container In order to place the reflector in the container of the limited volume in a closed state, a force of the reflector is set to exert a deformation stress on the reflector that is less than the creep strain limit of the reflector. Supplying to substantially opposite portions of the reflector adjacent the edge portion, maintaining the deformed state until the reflector is deployed, releasing the reflector from the deformed state and deploying the reflector from the container. A method comprising the steps of: 2. The method of claim 1, wherein maintaining the reflector comprises mounting suppression elements between substantially opposed portions of the reflector. 3. The method of claim 1, wherein the reflector comprises a parabolic shell. 4. A shell made of a flexible semi-rigid material having a predetermined creep strain limit in an antenna reflector foldable into and then deployable in a container of limited volume; A deforming force sufficient to place the reflector in a deformed state for folding at, but with a deformation exerted on the shell material not greater than the creep strain limit of the shell material, to substantially opposite portions of the shell. A reflector comprising means and means for releasing the reflector from a deformed state to facilitate deployment of the reflector from the container. 5. The shell has a paraboloidal shape.
The described reflector. 6. The shell is an integral structure.
The described reflector. 7. Folding an elastic antenna reflector having an original shape and having a predetermined creep strain limit into a container of limited volume not formed to hold the original shape, A method of deploying from a container, wherein the reflector is bent into a deformed shape different from the original shape so that the reflector can fit into and be held by the container, Folding the reflector in shape into the container, returning the reflector to substantially its original shape by bouncing the reflector, and deploying the reflector from the container in its original shape. 8. The method of claim 7, wherein a deformation is applied to the reflector during the bending step which is less than the predetermined creep strain limit of the reflector. 9. A suppressor element is attached to the reflector that holds the reflector in a deformed shape prior to the step of returning the reflector to its original shape, releasing the suppressor element to restore the reflector to its original shape. Return to the shape of
9. The method of claim 8, further comprising the step of facilitating deployment thereby.